高温煅烧石膏硅酸盐水泥早期水化产物的研究

利用DTA、XRD、IR、化学结合水和Ca(OH)2生成量测定等方法，研究了煅烧石膏、二水石膏对硅酸盐水泥早期水化过程的影响。结果表明：在水化龄期相同时，掺煅烧石膏水泥浆体中水化产物同掺二水石膏相比，Ca(OH)2生成量大；在一天前无心生成；结合水量在一天前前者高于后者，而一天后则相反。指出了煅烧石膏提高水泥强度的机理在于：由于煅烧石膏的溶解速度较低，在水泥水化初期(1d前)，存在于水泥中的铝酸盐相不能形成心，从而减缓了AFt对水泥水化的延缓作用，加速了整个熟料矿物相的水化，提高了水泥的强度。

Investigation on the Effect of Calcined-gypsum on the Early Hydration of Portland Cement

By experiment methods of DTA,XRD,IR,Chemical combined water analysis,Ca(OH)2 content and so forth,the effect of gypsum and calcined-gpysum on the early hydration of Portland Cement was investigated. The result showed that the hydrat product of the cement added calcined-gypsum has more Ca(OH)2 content during whole hydrating stage,less chemical combined water before 1 day and more after 1 day,and ettingite can not formed before 1 day comparaed with adding gypsum, .The reserch indicated that adding calcined-gypsum instead gypsum to cement can reinforce the early strength of cement, because the aluminate phase present in clinker can not hydrat to form ettringite during 1 day due to low dissolution rate of calcined-gypsum, so retarding action of ettingite on clinker hydration is decresed, the whole clinker mineral hydration is accelerated, the paste strength is incresed.